Showing papers on "Feed line published in 1977"

Triband vehicle antenna

Abstract: An antenna for simultaneous connection to a citizen's band transceiver, an AM receiver and a FM receiver, particularly suitable for use on a vehicle such as an automobile. The antenna proper is a center-loaded upstanding rod which, in the preferred form, telescopes downwardly to a retracted position where it does not protrude above the ground plane. The antenna proper is connected to a T-connected open stub transmission line and to a FM resonant relatively high impedance signal-carrying transmission line. The former has inductive reactance in the FM band which offsets the capacitive reactance of the relatively short effective length of the antenna proper in the FM frequencies. The signal-carrying transmission line is substantially half wave in length in the FM band so as to reflect impedance at its far end substantially equal to the impedance present at the T-connection. The signal-carrying transmission line is also of length that provides resonant action transforming the relatively low impedance at the T-connection or base of the antenna in the CB band to a higher impedance, such as 50 ohms, at the end of that transmission line. Finally, the signal-carrying transmission line, because of its relatively high characteristic impedance, has very low capacitance and therefore does not tend to load the AM radio. The end of the signal-carrying transmission line is connected to the input terminal of splitter containing resonant circuits which are in turn connected to two transmission lines, one leading to the CB transceiver and the other leading to the AM/FM radio.

Portable radio antenna

Abstract: PORTABLE RADIO ANTENNA ABSTRACT OF THE DISCLOSURE An antenna for a hand-held radio transceiver includes first and second elements extending from the radio's case. The first element is comprised of a pair of series coupled members having electrical lengths of one-half and one-quarter wavelength, respectively, with the free end of the second member being coupled to the transmitter output. The second element couples to the radio's electrical ground and is configured to form a transmission line with the second member. The effective electrical length of the second element, including the influence of the elements parasitic coupling to the radio, is adjusted to be one-quarter wave-length. The resulting antenna structure minimizes surface currents across the radio's body, thereby substantially eliminating power loss caused by absorption in the user's body.

Control system for hydrostatic transmission

Abstract: A hydrostatic transmission has an input connected to a prime mover and an output connected through a speed-change transmission to a load. A control element of this transmission is urged in a direction tending to increase the transmission ratio by a control cylinder pressurized from a hydraulic tachometer operated by the transmission input, and is urged in the opposite direction to decrease the ratio by a regulating cylinder connected via a feed line to the hydraulic network interconnecting the pump and motor of the transmission. During speed change the two cylinders are depressurized and the regulating cylinder is isolated from the network.

Circuit for wire transmission of high frequency data communication pulse signals

Abstract: A transceiver (transmitter-receiver) for high frequency data pulse signals is connected to a coaxial cable transmission line through a distributed delay line which has an impedance equal in value to the characteristic impedance of the coaxial cable transmission line. The transceiver transmitting and receiving circuits are tapped into the transmission line and form a part of the distributed delay line. When not in the transmitting mode, the transmitter circuit appears as a reactive element of the distributed delay line and thereby introduces minimum loss or reflection into the transmission line. The transmission line can serve as a trunk line for a number of transceivers by permitting virtually unrestricted multipoint connections to the line.

Microstrip switch wherein diodes are formed in single semiconductor body

Abstract: A microwave switch including a microstrip circuit having a plurality of strip conductors disposed on a planar surface of a dielectric substrate, a plurality of diodes having first electrodes connected to corresponding ones of the strip conductors, and a feed line disposed in a plane different from the planar surface of the substrate and connected to a second electrode of the diodes.

Broadband dipole antenna system with coaxial feed-line coated with ferrite particles to reduce line currents

Abstract: This disclosure deals with a three-element unit array (or stacked groups of the same) that enables the use of very large length-to-diameter dipole elements to cover broad frequency bands, greater than 2:1 in frequency ratio, by novel feed structures exciting the element gaps.

Antenna input circuit for AM/FM radio receiver

Abstract: An antenna input circuit for an AM/FM radio receiver comprises an input transformer for FM broadcast reception, an input transformer for AM broadcast reception, at least one antenna terminal for the connection of the transmission line leading from an FM-receiving antenna, and a filter network connecting the antenna terminal to each primary winding of those input transformers. The filter network is such that from the antenna terminal, it feeds, with little loss, FM broadcast signals to the FM input transformer, while it feeds, with an allowable amount of loss, AM broadcast signals to the AM input transformer. Thus, the antenna input circuit allows an AM/FM receiver to receive either an FM broadcast or an AM broadcast by using only a single antenna and without changing the connection of the antenna transmission line.

UHF antenna with air dielectric feed means

Abstract: A covert mobile communications omni-directional gain UHF antenna comprises a body having a U-shaped cavity and radiating slot, an L-shaped feed line and an end-loaded, open-circuited voltage probe. The antenna is tuneable by adjusting a pair of variable capacitors to match the impedance of the antenna to that of an attached coaxial cable and transceiver.

Extended impedance matching capabilities in the wide-band transmission line transformer

Abstract: Theory indicates that the transmission line transformer has the capability of perfectly matching, at a single frequency, any resistance ratio greater than four to one, and that it can maintain a close, although not perfect, match over a very broad frequency band for resistances whose ratio ranges from somewhat below to well above the commonly used value of four to one.

Improving the Frequency Characteristics of RF Standard Magnetic-Field Generator Employing Loop Antenna

Abstract: In the HF and VHF region, the standard magnetic-field generator having a loop antenna has been generally used for the calibration of a radio receiver or a field-strength meter. Presented are new standard magnetic field generators which are able to produce a constant magnetic field over a wide band frequency range by means of measuring the loop current through a compensation transmission line and a compensation thermination resistor. A magnetic-field generator in which a thermistor was used as both a compensation resistor and a current sensor was constructed and examined over the frequency range 10 to 50 MHz. The measured values were agreed with theoretical values within ±0.1 dB.

Apparatus for coupling microwave energy from two oscillators to a common transmission line

Abstract: A microwave system provides signals of two separate microwave frequencies, designated F.sub.(1) and F.sub.(2), alternately or simultaneously to a common coaxial transmission line by combining the outputs of two microwave frequency oscillators of frequencies F.sub.(1) and F.sub.(2). Each oscillator contains a waveguide output with which is associated at least one means, such as a resonant iris, for passing microwave energy of the oscillator's design frequency and for reflecting microwave energy of other frequencies, such as the different frequency of the other oscillator. A waveguide type transmission line is provided having first and second input ends and which line is of a length so as to be nonresonant at either of the two oscillator frequencies, F.sub.(1) or F.sub.(2). Each oscillator is coupled to a corresponding one of the two input ends of the waveguide. The waveguide is of a length in which signals of frequency F.sub.(1) form a field maxima at a certain location along the waveguide and in which signals of frequency F.sub.(2) form a field maxima along the waveguide at essentially the same said location. A microwave energy coupling probe is positioned in the waveguide at the location thereby defined to extract the microwave energy from the waveguide.

Apparatus for electrical feed of a heater in a crystal-growing vessel

Abstract: Apparatus for growing crystals comprising a vessel having a heater therein connected to electrical feed lines which extend from the vessel through a feed housing to an electrical supply source. The electrical feed line comprises inner and outer conductors which are electrically insulated through the provision of an intermediate electrically insulative conductor, the entire assembly being sealed separately for passage through the feed housing to the vessel.

Driving circuit for monostable oil hydraulic actuator

Abstract: PURPOSE:An oil hydraulic actuator which can be securely fixed while off action wherein thae hydraulic oil feed line and the drain oil line are arranged separately, the former line being provided with a spool type selector valve assembly and the latter with a poppet valve assembly.

Hydraulic operating system with change over valve - has changeover between two positions according to line pressure difference

Abstract: A hydraulic operating system has a changeover valve introduced between a feed line (29) to a hydraulic operator (25) with an inlet metering flow control valve (31) which is introduced into the feed line. An outlet-or return line (28) from the hydraulic operator has an oulet metering flow control valve (33), which is introduced into the outlet or return line. The changeover valve is changed over automatically between a first and second position according to the pressure difference in the feed- and outlet- or return lines. Each feed- and outlet or return line, which has a pressure which is less than that of the other line can be connected with a tank (22) by a low pressure unloading valve (39).

HF power cable for heating coil feed - has flat insulation on conductor strand and end couplers for strand wires

Abstract: The cable is intended to supply a high frequency voltage to an inductively heated evaporator. It has a feed line (10) with a number of adjacent, flexible conductors, mutually insulated by a coating, forming a flat flexible strip. The individual conductor ends, on both the voltage source and the evaporator side, have interconnecting terminals (21,22). A feed back line is found in the same manner as the feed line (10) and has identical ends intermitting terminals. The entire length of the cable, formed by the two lines are enclosed in a common sheath (12) which permits length shifts of the respective lines. The edges of the insulating strips of both lines are interconnected into a simple structure.

Microwave Air Strip Transmission Line for S-Band

Abstract: A low-loss microwave shielded air strip transmission line has been fabricated using a dielectric material Tellite and 3 cm waveguide as a substitute for waveguides in the 5-Band 10 cm region. This has made it possible to use strip line transmission for long distances, such as used in marine radars. It has the added advantage of reduced cost and size over waveguides normally used in 10 cm region.